Cooling system for a natural gas engine and method of controlling the same

Abstract

The application discloses a cooling system of a natural gas engine and a control method thereof. The method comprises the following steps: after the natural gas engine is started, the natural gas temperature, the intake air temperature and the engine outlet water temperature of the cooling system are monitored in real time; based on the natural gas temperature, the state of a first control valve is controlled to adjust the water circuit of the cooling system to warm up the natural gas in a carburettor; based on the intake air temperature, the state of a second control valve is controlled to adjust the water circuit of the cooling system to cool down the exhaust gas in an EGR cooler; and based on the engine outlet water temperature, the state of a third control valve is controlled to adjust the water circuit of the cooling system to cool down the cooling water of the cooling system. The method controls the respective control valves of the carburettor, the EGR cooler and the radiator to adjust the water circuit of the cooling system, so that the natural gas temperature, the intake air temperature and the engine outlet water temperature are maintained within a reasonable range, and the accurate control of the natural gas temperature in the natural gas engine is realized.

Description

Technical Field

[0001] The present application relates to the field of natural gas engines, and in particular to a cooling system of a natural gas engine and a control method thereof. Background Art

[0002] Natural gas engine fuel, primarily composed of methane, produces fewer harmful emissions than gasoline and other fuels, making it more environmentally friendly. Based on the fuel's form, engines can be categorized as compressed natural gas (CNG) and liquefied natural gas (LNG). CNG is compressed and stored in high-pressure cylinders, resulting in a higher operating pressure, while LNG is liquefied natural gas and stored at a higher density. LNG engines (abbreviated as LNG gas engines) are currently widely used in buses, heavy trucks, and other vehicles, reducing exhaust pollution and lowering operating costs.

[0003] The natural gas temperature in LNG engines must be controlled within a certain range, neither too high nor too low. When the natural gas temperature is low, the combustion reaction slows down. This results in incomplete combustion of the fuel, affecting the engine's power and economy. When the natural gas temperature is too high, the final mixture in the combustion chamber can easily ignite due to the high temperature and pressure before the flame front reaches it, causing detonation. Excessively high gas temperatures also increase the thermal load on components such as pistons and valves, generating thermal stress and damaging the engine.

[0004] Therefore, how to accurately control the natural gas temperature of the LNG gas generator has become an urgent problem to be solved. Summary of the Invention

[0005] The present application provides a cooling system for a natural gas engine and a control method thereof, the purpose of which is to accurately control the natural gas temperature of the LNG gas engine.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A cooling system for a natural gas engine, comprising:

[0008] Water pump, components to be cooled, carburetor, EGR cooler, radiator, temperature monitoring module and water circuit control module;

[0009] The water pump is used to provide cooling water to the water channel of the cooling system;

[0010] The temperature monitoring module comprises a first sensor, a second sensor and a third sensor; the first sensor is arranged on the carburetor to monitor the natural gas temperature in the carburetor; the second sensor is arranged on the EGR cooler to monitor the intake air temperature of the EGR cooler; and the third sensor is arranged on the water circuit where the component to be cooled is located to monitor the engine outlet water temperature.

[0011] The water circuit control module comprises a first control valve, a second control valve and a third control valve; the first control valve is arranged on the water circuit where the carburetor is located to control the water circuit where the carburetor is located to participate in the water circulation of the cooling system; the second control valve is arranged on the water circuit where the EGR cooler is located to control the water circuit where the EGR cooler is located to participate in the water circulation of the cooling system; and the third control valve is arranged on the water circuit where the radiator is located to control the water circuit where the radiator is located to participate in the water circulation of the cooling system.

[0012] Optionally, when the natural gas temperature is less than a first calibration temperature, the first control valve is in an open state, the water circuit where the carburetor is located participates in the water circulation of the cooling system, so that the cooling water warms up the natural gas in the carburetor; when the natural gas temperature is greater than a second calibration temperature, the first control valve is in a closed state, the water circuit where the carburetor is located does not participate in the water circulation of the cooling system; and the first calibration temperature is less than the second calibration temperature.

[0013] Optionally, when the intake air temperature is greater than or equal to a third calibration temperature, the second control valve is in an open state, the water circuit where the EGR cooler is located participates in the water circulation of the cooling system, so that the cooling water cools down the exhaust gas in the EGR cooler; when the intake air temperature is less than the third calibration temperature, the second control valve is in a closed state, the water circuit where the EGR cooler is located does not participate in the water circulation of the cooling system.

[0014] Optionally, when the engine outlet water temperature is greater than a fourth calibration temperature, the third control valve is controlled to be in an open state, the water circuit where the radiator is located participates in the water circulation of the cooling system, so that the radiator cools down the cooling water; when the engine outlet water temperature is less than or equal to the fourth calibration temperature, the third control valve is controlled to be in a closed state, the water circuit where the radiator is located does not participate in the water circulation of the cooling system.

[0015] A control method applied to the cooling system, the method comprising:

[0016] After the natural gas engine is started, the natural gas temperature, the intake air temperature and the engine outlet water temperature of the cooling system are monitored in real time.

[0017] controlling a state of the first control valve based on the natural gas temperature to regulate a water circuit of the cooling system to warm up the natural gas in the carburetor;

[0018] controlling a state of the second control valve based on the intake air temperature to regulate a water circuit of the cooling system to cool down the exhaust gas in the EGR cooler;

[0019] controlling a state of the third control valve based on the engine outlet water temperature to regulate a water circuit of the cooling system to cool down the cooling water of the cooling system.

[0020] Optionally, the controlling the state of the first control valve based on the natural gas temperature to regulate the water circuit of the cooling system to warm up the natural gas in the carburetor comprises:

[0021] when the natural gas temperature is less than a first calibration temperature, triggering the water circuit in which the carburetor is located to participate in the water circulation of the cooling system by controlling the first control valve to be in an open state, so that the cooling water of the cooling system warms up the natural gas in the carburetor;

[0022] when the natural gas temperature is greater than a second calibration temperature, triggering the water circuit in which the carburetor is located not to participate in the water circulation of the cooling system by controlling the first control valve to be in a closed state; the first calibration temperature is less than the second calibration temperature.

[0023] Optionally, the controlling the state of the second control valve based on the intake air temperature to regulate the water circuit of the cooling system to cool down the exhaust gas in the EGR cooler comprises:

[0024] when the intake air temperature is greater than or equal to a third calibration temperature, triggering the water circuit in which the EGR cooler is located to participate in the water circulation of the cooling system by controlling the second control valve to be in an open state, so that the cooling water of the cooling system cools down the exhaust gas in the EGR cooler;

[0025] when the intake air temperature is less than the third calibration temperature, triggering the water circuit in which the EGR cooler is located not to participate in the water circulation of the cooling system by controlling the second control valve to be in a closed state.

[0026] Optionally, the controlling the state of the third control valve based on the engine outlet water temperature to regulate the water circuit of the cooling system to cool down the cooling water of the cooling system comprises:

[0027] when the engine outlet water temperature is greater than a fourth calibration temperature, triggering the water circuit in which the radiator is located to participate in the water circulation of the cooling system by controlling the third control valve to be in an open state, so that the radiator cools the cooling water;

[0028] when the engine outlet water temperature is less than or equal to the fourth calibration temperature, triggering the water circuit in which the radiator is located not to participate in the water circulation of the cooling system by controlling the third control valve to be in a closed state.

[0029] Optionally, the control method further comprises:

[0030] when the natural gas temperature is greater than or equal to the first calibration temperature and less than or equal to the second calibration temperature, adjusting the temperature rising rate of the natural gas in the vaporizer by controlling the opening degree of the first control valve in the open state; wherein the opening degree is in a positive correlation with the temperature rising rate.

[0031] A vehicle, comprising a processor, a memory and a bus, the processor being connected with the memory through the bus, the memory being used for storing a program, and the processor being used for running the program, wherein the program performs the control method described above when running.

[0032] The technical scheme provided in the application can cut off the water circuit of the EGR cooler when the natural gas temperature is low and the intake air temperature is low (i.e. the intake air temperature is less than a third calibration temperature), so that the water circuit in which the EGR cooler is located does not participate in the water circulation of the cooling system, thus reducing the actual water capacity circulating in the water circuit of the cooling system, improving the temperature rising rate of the natural gas, shortening the heating waiting time of the liquid natural gas, closing the water circuit of the vaporizer (i.e. the water circuit in which the vaporizer is located does not participate in the water circulation of the cooling system) in a high temperature state (i.e. the natural gas temperature is greater than or equal to a second calibration temperature), preventing the natural gas temperature from being too high, and thus controlling the natural gas temperature within a reasonable range. In addition, the opening degree of the second control valve can be controlled according to the intake air temperature, so that the intake air temperature is maintained within a reasonable range, and the risk of misfire or knock is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical schemes in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0034] Figure 1 An architectural schematic diagram of a cooling system of a natural gas engine is provided for the embodiments of the application;

[0035] Figure 2 A control method schematic diagram provided for an embodiment of the present application;

[0036] Figure 3 A waterway working schematic diagram of a cooling system provided for an embodiment of the present application;

[0037] Figure 4 A waterway working schematic diagram of a cooling system provided for another embodiment of the present application;

[0038] Figure 5 A waterway working schematic diagram of a cooling system provided for another embodiment of the present application;

[0039] Figure 6 A waterway working schematic diagram of a cooling system provided for another embodiment of the present application;

[0040] Figure 7 A control method schematic diagram provided for another embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work fall within the protection scope of the present application.

[0042] In the present application, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations, the term “comprise”, “include” or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement “comprise a” does not exclude the presence of another identical element in the process, method, article or equipment including the element.

[0043] As Figure 1 shown, a schematic diagram of an architecture of a cooling system of a natural gas engine provided for an embodiment of the present application, the cooling system of the natural gas engine can be applied to a vehicle, including the following components.

[0044] The water pump 1, the components to be cooled (including the oil cooler 2, the engine water jacket 3, the cylinder head water jacket 4, and the water outlet pipe 5), the carburetor 6, the EGR cooler 7, the radiator 9, the temperature monitoring module (including the first sensor 11, the second sensor 12, and the third sensor 10), and the water circuit control module (including the first control valve 13, the second control valve 14, and the third control valve 8).

[0045] In some examples, the first sensor 11, the second sensor 12, and the third sensor 10 are temperature sensors.

[0046] In some examples, the first sensor 11 can be regarded as a natural gas temperature sensor (or simply a gas temperature sensor), the second sensor 12 can be regarded as an intake air temperature sensor, and the third sensor 10 can be regarded as an engine water temperature sensor (or simply a water temperature sensor).

[0047] In some examples, the first control valve 13 can be regarded as a carburetor water circuit control valve, the second control valve 14 can be regarded as an EGR cooler water circuit control valve, and the third control valve 8 can be regarded as a water outlet control valve.

[0048] The so-called components to be cooled can be understood as components that generate heat during engine operation and are cooled.

[0049] The so-called carburetor 6 is specifically used to heat liquid natural gas to a gaseous state by the cooling water of the engine for natural gas engine combustion.

[0050] The so-called EGR cooler 7 refers to a cooling device of the EGR (Exhaust Gas Recirculation) system.

[0051] The water pump 1 is used to provide cooling water for the water circuit of the cooling system. Generally, the water circuit of the cooling system is a circulating water circuit.

[0052] The first sensor 11 is disposed on the carburetor 6 and is used to monitor the temperature of the natural gas in the carburetor 6.

[0053] In possible implementations, the first sensor 11 can be installed at a position before the carburetor 6 mixes with fresh air.

[0054] The second sensor 12 is disposed on the EGR cooler 7 and is used to monitor the intake air temperature of the EGR cooler 7.

[0055] In possible implementations, the second sensor 12 can be installed at the intake port of the EGR cooler 7.

[0056] The third sensor 10 is disposed on the water circuit where the components to be cooled are located and is used to monitor the engine water outlet temperature.

[0057] In possible embodiments, the third sensor 10 is installed on the water path where the component to be cooled is located and passes the position of the component to be cooled.

[0058] The first control valve 13 is disposed on the water path where the carburetor 6 is located and is used to control the water path where the carburetor 6 is located to participate in the water circulation of the cooling system.

[0059] In possible embodiments, the first control valve 13 can be installed at a position upstream of the corresponding region of the carburetor 6 in the water path where the carburetor 6 is located.

[0060] The second control valve 14 is disposed on the water path where the EGR cooler 7 is located and is used to control the water path where the EGR cooler 7 is located to participate in the water circulation of the cooling system.

[0061] In possible embodiments, the second control valve 14 can be installed at a position upstream of the corresponding region of the EGR cooler 7 in the water path where the EGR cooler 7 is located.

[0062] The third control valve 8 is disposed on the water path where the radiator 9 is located and is used to control the water path where the radiator 9 is located to participate in the water circulation of the cooling system.

[0063] In possible embodiments, one end of the third control valve 8 is connected to the water outlet pipe, and the other end is connected to the water pump 1 (so that the cooling water can directly flow back to the water pump 1) and the radiator 9 (so that the cooling water flows back to the water pump 1 after passing through the radiator 9) respectively.

[0064] Optionally, when the natural gas temperature is less than the first specified temperature, the first control valve 13 is in an open state, and the water path where the carburetor 6 is located participates in the water circulation of the cooling system, so that the cooling water warms up the natural gas in the carburetor 6; when the natural gas temperature is greater than the second specified temperature, the first control valve 13 is in a closed state, and the water path where the carburetor 6 is located does not participate in the water circulation of the cooling system; the first specified temperature is less than the second specified temperature.

[0065] In some examples, when the natural gas temperature is less than the first specified temperature, the second control valve 14 can be placed in a closed state, so that the water path where the EGR cooler 7 is located does not participate in the water circulation of the cooling system, resulting in a decrease in the water capacity of the cooling system in operation, thereby increasing the warming rate of the temperature of the cooling water (i.e., the engine outlet water temperature).

[0066] It should be noted that when the first control valve 13 is in an open state, the opening degree of the first control valve 13 can be adjusted according to the temperature of the natural gas. Generally, the lower the temperature of the natural gas, the greater the opening degree of the first control valve 13, so that the warming rate of the natural gas in the carburetor 6 is increased, and the higher the temperature of the natural gas, the smaller the opening degree of the first control valve 13, so that the warming rate of the natural gas in the carburetor 6 is decreased, thereby avoiding the warming rate of the natural gas in the carburetor 6 being too fast.

[0067] Optionally, when the intake air temperature is greater than or equal to the third calibration temperature, the second control valve 14 is in an open state, the water circuit in which the EGR cooler 7 is located participates in the water circulation of the cooling system, so that the cooling water cools the exhaust gas in the EGR cooler 7; when the intake air temperature is less than the third calibration temperature, the second control valve 14 is in a closed state, the water circuit in which the EGR cooler 7 is located does not participate in the water circulation of the cooling system.

[0068] It should be noted that when the intake air temperature is greater than or equal to the third calibration temperature, it can be determined that the temperature of the exhaust gas in the EGR cooler 7 is relatively high, and the cooling water needs to be used to cool the exhaust gas.

[0069] Optionally, when the engine water outlet temperature is greater than the fourth calibration temperature, the third control valve 8 is controlled to be in an open state, the water circuit in which the radiator 9 is located participates in the water circulation of the cooling system, so that the cooling water is cooled by the radiator 9; when the engine water outlet temperature is less than or equal to the fourth calibration temperature, the third control valve 8 is controlled to be in a closed state, the water circuit in which the radiator 9 is located does not participate in the water circulation of the cooling system.

[0070] It should be noted that when the engine water outlet temperature is greater than the fourth calibration temperature, it can be determined that the temperature of the cooling water is relatively high, and the radiator 9 needs to be used to cool the cooling water.

[0071] In some examples, the working schematic diagram of the water circuit of the cooling system of the natural gas engine can be seen from Figures 3-6 (shown by a dashed line, the water circuit is not connected or disconnected).

[0072] Specifically, when the natural gas temperature is low (the natural gas temperature is less than the first calibration temperature), the EGR cooler 7 does not work (the water circuit in which the EGR cooler 7 is located does not participate in the water circulation of the cooling system), and the cooling water small circulation (the water circuit in which the radiator 9 is located does not participate in the water circulation of the cooling system), the water circuit of the cooling system is as shown in Figure 3 .

[0073] Specifically, when the natural gas temperature is low (the natural gas temperature is less than the first calibration temperature), the EGR cooler 7 works (the water circuit in which the EGR cooler 7 is located participates in the water circulation of the cooling system), and the cooling water small circulation (the water circuit in which the radiator 9 is located does not participate in the water circulation of the cooling system), the water circuit of the cooling system is as shown in Figure 4 .

[0074] Specifically, when the natural gas temperature is high (the natural gas temperature is greater than or equal to the second calibration temperature), the EGR cooler 7 does not work (the water circuit in which the EGR cooler 7 is located does not participate in the water circulation of the cooling system), and the cooling water large circulation (the water circuit in which the radiator 9 is located participates in the water circulation of the cooling system), the water circuit of the cooling system is as shown in Figure 5 .

[0075] Specifically, when the natural gas temperature is high (the natural gas temperature is greater than or equal to the second calibration temperature), the EGR cooler 7 works (the water circuit in which the EGR cooler 7 is located participates in the water circulation of the cooling system), and the cooling water is circulated (the water circuit in which the radiator 9 is located participates in the water circulation of the cooling system), the water circuit of the cooling system is as shown in Figure 6 .

[0076] The above-mentioned various components can cut off the water circuit of the EGR cooler when the natural gas temperature is low and the intake air temperature is low (that is, the intake air temperature is less than the third calibration temperature), so that the water circuit in which the EGR cooler is located does not participate in the water circulation of the cooling system, thus reducing the actual water capacity circulating in the water circuit of the cooling system, improving the heating rate of the natural gas temperature, shortening the heating waiting time of the liquid natural gas, closing the water circuit of the vaporizer in the high temperature state (that is, the water circuit in which the vaporizer is located does not participate in the water circulation of the cooling system), preventing the natural gas temperature from being too high, and thus controlling the natural gas temperature within a reasonable range. In addition, the opening of the second control valve can be controlled according to the intake air temperature, so that the intake air temperature is maintained within a reasonable range, and the risk of misfire or knock is reduced.

[0077] As shown in Figure 2 , a control method provided by the embodiment of the application is suitable for a cooling system of a natural gas engine, and includes the following steps.

[0078] S201: After the natural gas engine is started, the natural gas temperature, the intake air temperature, and the engine outlet water temperature of the cooling system are monitored in real time.

[0079] S202: Based on the natural gas temperature, the state of the first control valve is controlled to adjust the water circuit of the cooling system to heat the natural gas in the vaporizer.

[0080] Optionally, the implementation process of controlling the state of the first control valve based on the natural gas temperature to adjust the water circuit of the cooling system to heat the natural gas in the vaporizer includes: when the natural gas temperature is less than the first calibration temperature, the first control valve is controlled to be in an open state, the water circuit in which the vaporizer is located is triggered to participate in the water circulation of the cooling system, so that the cooling water of the cooling system heats the natural gas in the vaporizer; when the natural gas temperature is greater than the second calibration temperature, the first control valve is controlled to be in a closed state, the water circuit in which the vaporizer is located is triggered not to participate in the water circulation of the cooling system; the first calibration temperature is less than the second calibration temperature.

[0081] Optionally, when the natural gas temperature is greater than or equal to the first calibration temperature and less than or equal to the second calibration temperature, the opening of the first control valve in the open state is controlled to adjust the heating rate of the natural gas in the vaporizer; wherein the opening and the heating rate are in a positive proportional relationship.

[0082] S203: Based on the intake air temperature, control the state of the second control valve to adjust the water circuit of the cooling system to cool the exhaust gas in the EGR cooler.

[0083] Optionally, the implementation process of controlling the state of the second control valve based on the intake air temperature to adjust the water circuit of the cooling system to cool the exhaust gas in the EGR cooler is as follows: when the intake air temperature is greater than or equal to the third calibration temperature, by controlling the second control valve to be in the open state, triggering the water circuit in which the EGR cooler is located to participate in the water circulation of the cooling system, so that the cooling water of the cooling system cools the exhaust gas in the EGR cooler; when the intake air temperature is less than the third calibration temperature, by controlling the second control valve to be in the closed state, triggering the water circuit in which the EGR cooler is located to not participate in the water circulation of the cooling system.

[0084] S204: Based on the engine water outlet temperature, control the state of the third control valve to adjust the water circuit of the cooling system to cool the cooling water of the cooling system.

[0085] Optionally, the implementation process of controlling the state of the third control valve based on the engine water outlet temperature to adjust the water circuit of the cooling system to cool the cooling water of the cooling system is as follows: when the engine water outlet temperature is greater than the fourth calibration temperature, by controlling the third control valve to be in the open state, triggering the water circuit in which the radiator is located to participate in the water circulation of the cooling system, so that the radiator cools the cooling water; when the engine water outlet temperature is less than or equal to the fourth calibration temperature, by controlling the third control valve to be in the closed state, triggering the water circuit in which the radiator is located to not participate in the water circulation of the cooling system.

[0086] In some examples, the first sensor is regarded as a natural gas temperature sensor, the second sensor is regarded as an intake air temperature sensor, the third sensor is regarded as an engine water temperature sensor, the first control valve is regarded as a vaporizer water circuit control valve, the second control valve is regarded as an EGR cooler water circuit control valve, and the third control valve is regarded as a water outlet control valve. The control logic of the cooling system of the natural gas engine can also refer to Figure 7 As shown, it can be summarized as steps 1-11.

[0087] Step 1: The natural gas engine reaches the starting condition and ignites to start.

[0088] Specifically, steps 2-5 can be regarded as the control process of the vaporizer.

[0089] Step 2: According to the test signal of the natural gas temperature sensor, it is determined whether the natural gas temperature reaches T1 (i.e., the first calibration temperature). If the natural gas temperature is less than T1, it is determined that the natural gas is difficult to be vaporized and combusted in the engine cylinder, and step 3 is entered. If the natural gas temperature is greater than or equal to T1, it is determined that the natural gas can be vaporized and combusted in the engine cylinder, and step 4 is entered.

[0090] Step 3: When the natural gas temperature is low, the vaporizer water control valve is opened, and the cooling water heats the natural gas.

[0091] Step 4: It is determined whether the natural gas temperature is too high. If the natural gas temperature is less than T2 (i.e., the second calibration temperature), the opening of the vaporizer water control valve is controlled according to the natural gas temperature. If the natural gas temperature is greater than or equal to T2, step 5 is entered. The higher the natural gas temperature, the smaller the corresponding opening.

[0092] Step 5: The vaporizer water control valve is closed, and the cooling water stops heating the natural gas, returning to step 2.

[0093] Specifically, steps 6-8 can be regarded as the control process of the EGR cooler.

[0094] Step 6: According to the test signal of the intake air temperature sensor, it is determined whether the intake air temperature is too high. If the intake air temperature is less than T3 (i.e., the third calibration temperature), step 7 is entered. If the intake air temperature is greater than or equal to T3, step 8 is entered.

[0095] Step 7: The EGR cooler water control valve is closed, and the water in the EGR cooler does not participate in the water circulation of the cooling system. The exhaust gas through the EGR heats the fresh air at low temperature to increase the intake air temperature, and step 6 is returned.

[0096] Step 8: The EGR cooler water control valve is opened, and the water in the EGR cooler participates in the water circulation of the cooling system, so that the intake air temperature is reduced, and step 6 is returned.

[0097] Step 9: According to the test signal of the engine water temperature sensor, it is determined whether the engine water temperature is too high. If the engine water temperature is less than T4 (i.e., the fourth calibration temperature), step 10 is entered. If the engine water temperature is greater than or equal to T4, step 11 is entered.

[0098] Step 10: The outlet control valve opens the water path to the water pump and closes the water path to the radiator, so that the water in the radiator does not participate in the water circulation of the cooling system, and step 9 is returned.

[0099] Step 11: The outlet control valve closes the water path to the water pump and opens the water path to the radiator, so that the water in the radiator participates in the circulation and is cooled, and step 6 is returned.

[0100] The above-mentioned flow shown in S201-S204, by controlling the waterway corresponding to the vaporizer and the EGR cooler respectively, the temperature of natural gas and the temperature of intake air are maintained within a reasonable range, which has a significant performance improvement in improving the control accuracy of natural gas temperature and optimizing the engine in-cylinder combustion.

[0101] The application further provides a computer readable storage medium, which comprises a stored program, wherein the program executes the control method provided by the application.

[0102] The application further provides a vehicle, comprising a processor, a memory and a bus. The processor is connected with the memory through the bus, the memory is used for storing a program, and the processor is used for running the program, wherein the program executes the control method provided by the application when running.

[0103] Although the above discussion contains a number of specific implementation details, these should not be construed as limiting the scope of the application. Certain features described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented separately or in any suitable subcombination. It will be appreciated that certain features of the disclosed implementations can be used to advantage without the benefit of other features. Thus, the application is not limited to the specific implementations described in this specification.

[0104] The above description is merely preferred embodiments of the application and a description of the principles of the technology used. Those skilled in the art should understand that the disclosed scope of the application is not limited to the technical solutions formed by the specific combinations of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features disclosed in the application (but not limited to) having similar functions to form technical solutions.

Claims

1. A cooling system for a natural gas engine, characterized in that Comprising: a water pump, a component to be cooled, a carburetor, an EGR cooler, a radiator, a temperature monitoring module, and a water circuit control module; the water pump is configured to provide cooling water for a water circuit of the cooling system; the temperature monitoring module comprises a first sensor, a second sensor, and a third sensor; the first sensor is disposed on the carburetor and configured to monitor a natural gas temperature in the carburetor; the second sensor is disposed on the EGR cooler and configured to monitor an intake air temperature of the EGR cooler; the third sensor is disposed on a water circuit where the component to be cooled is located and configured to monitor an engine outlet water temperature; the water circuit control module comprises a first control valve, a second control valve, and a third control valve; the first control valve is disposed on a water circuit where the carburetor is located and configured to control the water circuit where the carburetor is located to participate in a water circulation of the cooling system; the second control valve is disposed on a water circuit where the EGR cooler is located and configured to control the water circuit where the EGR cooler is located to participate in the water circulation of the cooling system; the third control valve is disposed on a water circuit where the radiator is located and configured to control the water circuit where the radiator is located to participate in the water circulation of the cooling system; wherein, when the natural gas temperature is less than a first calibration temperature, the first control valve is in an open state, the water circuit where the carburetor is located participates in the water circulation of the cooling system, so that the cooling water warms up the natural gas in the carburetor; when the natural gas temperature is greater than a second calibration temperature, the first control valve is in a closed state, the water circuit where the carburetor is located does not participate in the water circulation of the cooling system; the first calibration temperature is less than the second calibration temperature; when the intake air temperature is greater than or equal to a third calibration temperature, the second control valve is in an open state, the water circuit where the EGR cooler is located participates in the water circulation of the cooling system, so that the cooling water cools down the exhaust gas in the EGR cooler; when the intake air temperature is less than the third calibration temperature, the second control valve is in a closed state, the water circuit where the EGR cooler is located does not participate in the water circulation of the cooling system.

2. The cooling system of claim 1, wherein, when the engine outlet water temperature is greater than a fourth calibration temperature, the third control valve is controlled to be in an open state, the water circuit where the radiator is located participates in the water circulation of the cooling system, so that the radiator cools down the cooling water; when the engine outlet water temperature is less than or equal to the fourth calibration temperature, the third control valve is controlled to be in a closed state, the water circuit where the radiator is located does not participate in the water circulation of the cooling system.

3. A control method characterized by, The method is applied to the cooling system of any one of the above claims 1-2, and the method comprises: monitoring the natural gas temperature, the intake air temperature, and the engine outlet water temperature of the cooling system in real time after the natural gas engine starts; based on the natural gas temperature, control the state of the first control valve to adjust the water circuit of the cooling system to warm up the natural gas in the carburetor; wherein, when the natural gas temperature is less than a first calibration temperature, by controlling the first control valve to be in an open state, triggering the water circuit where the carburetor is located in the cooling system to participate in the water circulation of the cooling system, so that the cooling water of the cooling system warms up the natural gas in the carburetor; when the natural gas temperature is greater than a second calibration temperature, by controlling the first control valve to be in a closed state, triggering the water circuit where the carburetor is located not to participate in the water circulation of the cooling system; the first calibration temperature is less than the second calibration temperature; based on the intake air temperature, control the state of the second control valve to adjust the water circuit of the cooling system to cool the exhaust gas in the EGR cooler; wherein, when the intake air temperature is greater than or equal to a third calibration temperature, by controlling the second control valve to be in an open state, triggering the water circuit where the EGR cooler is located in the cooling system to participate in the water circulation of the cooling system, so that the cooling water of the cooling system cools the exhaust gas in the EGR cooler; when the intake air temperature is less than the third calibration temperature, by controlling the second control valve to be in a closed state, triggering the water circuit where the EGR cooler is located not to participate in the water circulation of the cooling system; based on the engine outlet water temperature, control the state of the third control valve to adjust the water circuit of the cooling system to cool the cooling water of the cooling system.

4. The control method according to claim 3, characterized by based on the engine outlet water temperature, control the state of the third control valve to adjust the water circuit of the cooling system to cool the cooling water of the cooling system, comprising: when the engine outlet water temperature is greater than a fourth calibration temperature, by controlling the third control valve to be in an open state, triggering the water circuit where the radiator is located in the cooling system to participate in the water circulation of the cooling system, so that the radiator cools the cooling water; when the engine outlet water temperature is less than or equal to the fourth calibration temperature, by controlling the third control valve to be in a closed state, triggering the water circuit where the radiator is located not to participate in the water circulation of the cooling system.

5. The control method according to claim 4, characterized by The control method further comprises: when the natural gas temperature is greater than or equal to the first calibration temperature and less than or equal to the second calibration temperature, by controlling the opening degree of the first control valve in the open state, to adjust the warming rate of the natural gas in the carburetor; wherein, the opening degree is in a positive correlation with the warming rate.

6. A vehicle characterized by comprising: comprising: a processor, a memory and a bus, the processor and the memory are connected through the bus, the memory is used to store programs, and the processor is used to run programs, wherein, the program executes the control method of any one of the above claims 3-5 when running.

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